Mechanism for controlling and operating the valves of hydrocarbon-engines.



G. E. DAVIS.

MECHANISM FOR CONTROLLING AND OPERATING THE VALVES 0F HYDROCARBON ENGINES.

APPLICATION FILED JULY 6.19I2.

1 20%,4 1 5 Patented Nov. 14, 1916.

4 SHIEETS-SHEET 1.

e. E. DAVIS.

MECHANISM-FOR CONTROLLING AND OPERATING THE VALVES 0F HYDROCARBON ENGINES.

APPLICATlON FILED JULY 6.1912.

1,204,415. Patented Nov. 14, 1916.

' 4 SHEETS-SHEET 2 Z9 10? 28 2527 I 5 L q I .25 L 1L LL" 1 L E/ 5 4 Lb IL V I 22 J8 g a, I Z g 10 a I Y A L 7.4 2, r I a d 1L3; B I L 7 16 m1 NGNN'S Farm: to PHOTD urlm WASNINGIJN, a c

G. E. DAVIS. MECHANISM'FOR CONTROLLING AND OPERATING THE VALVES 0F HYDROCARBON ENGINES- APPLlCATlON FILED JULY 6, I912. v 1204,41 5. Patented Nov. 14, 1916.

4 SHEETS-SHEET 3.

he zaew ad rNr mmms PETERS m. pnmv-umou WASHINGTVN. n c,

G. E. DAViS.

MECHANISM FOR CONTROLLING AND OPERATING THE VALVES 0F HYDROCARBON ENGINES.

APPLICATION FILED JULY 6.1912.

24,415. Patented Nov. 14, 1916.

4 SHEETSSHEET 4.

1:1:m:HNNNN i GEORGE EDWARD DAVIS, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR OF FIFTY-FIVE ONE-HUNDREDTHS TO GEORGE W. RICHARDSON, OF CHICAGO, ILLINOIS, AND FOETY-FIVE ONE-I'IUNDREIDTHS TO HENRY A. GEISERT, OF JEFFERSON CITY, MIS- SOURI.

MECHANISM FOR CONTROLLING AND OPERATING TI-IE VALVES OF I-IYDROCARBON- ENGINES.

Specification of Letters Patent.

Patented Nov. 1%, 1916.

Application filed July 6, 1912. Serial No. 707,995.

To all whom it may concern Be it known that I, GEORGE EDWARD DAVIS, a citizen of the United States, residing at Pittsburgh, in the county of Allegheny and the State of Pennsylvania, have invented certain new and useful Improvements in Mechanism for Controlling and Operating the Valves of Hydrocarbon- Engines.

My improvements consist in the following:

First :R-educing the motion of the valve cams by an arrangement of reduction gears, planetary or otherwise, between the crank shaft and the cam shaft, on which the cam plate is afliXed, on a reduction ratio of four (4L) to one (1) or eight (8) to one (1) between the same moving bodies, as may be found convenient. I can also make the reduction ratio two (2) to one (1) as is found in the present type of engines, with advantages over the present usage which will be made apparent later on.

Second z-Duplexing the valve cam or cams so that it or they on one complete revolution may transmit two (2) or more impulses to each cylinder coming under the radius of control, this number of impulses depending on the reduction ratios between the crank shaft and the cam shaft, thereby making the cam and its attachments a double or quadruple acting unit on each revolution, and making the power necessary to drive and operate the valves one half or one fourth over what prevails at present.

Third :The placing of all valves and spark plugs on one (1) or more concentric circular lines of travel, the centers of these circles to correspond with the center of rotation of the cam shaft and the placement of the exhaust and inlet valves of any one cylinder on these concentric circles in such a way that their angular distance apart, measured at the common center of the circles of placement, with slight variations to meet economic engine design, shall be proportional to the amount of reduction between the crank shaft and the cam shaft. The number of concentric circular lines of travel will be governed by the amount of reduction between the crank shaft and cam shaft, the number of cylinders and their crank throws and also whether the duplexing feature mentioned above is availed of.

The ways and means by which I bring about these results can be seen by reference to the accompanying drawings and specification and their attendant figures of reference, illustrating a four (4) cylinder four l) cycle operated engine, fitted with my system of unit control.

Figure 1 is a front elevation of such engine, a pair of cylinders appearing in cross section on line D D, Fig. 2. Fig. 2 is a top plan. Fig. 3 shows a plan of a pair of cylinders on a larger scale. Fig. I is a vertical cross section through the revolving disk, timer, valve and cylinder heads and sparking device on a line 0 0 of Fig. 3. Fig. 5 is a horizontal cross section through the gas chamber of a pair of cylinder heads on a line B B, Figs. 1 and a. Fi 6 is the same through the water chamber on a line A A, Figs. 1 and 4:. Fig. 7 shows in perspective the cam bottom side up, illustrating the projecting lugs or cam raisers for operating the valves, the sparking cams being shown in broken section. Fig. 8 is an elevation of the reduction gear by which motion is transmitted from the crank shaft to the cam shaft. Fig. 9 is a plan of the same reduction gears. Fig. 10 is a plan of the ratchet coupling between the cam shaft and the engine shaft which releases the valve and sparking operation, in event of back firing.

In Fig. 1, 1 represents cylinders, within which work pistons (2), with the usual rings (3) connected by connecting rods (4:) in the usual way, to crank pins of crank shaft (5) working in brass bearings (6). The cylinders are provided with the usual cooling jackets (7) and surmount the usual crank case (8). The vertical shaft (9) imparts motion from the crank shaft (5) to the rotary cam (10) by means of the reduction gears (11), the shaft (9) being stepped into a ratchet joint or coupling (83). This ratchet joint or coupling (33) is shown here and in more detail in Fig. 8 to be placed above the reduction gears (11) but it can be placed just as well and perhaps more advantageously below the reduction gears. The reduction gears (11) are connected within the crank case (8) by miter gears (34), these reduction gears being also shown on a larger scale in Figs. 8 and 9. The cam plate (10) rotates in a horizontal plane at right angles to the vertical shaft (9). On the under side of the cam plate (10) are placed the lugs (12) which bear upon the valve stems (13) thereby operating the valves (14). The cam shaft (9) is placed between a pair of cylinders in a brass bearing or sleeve (15). This brass bearing or sleeve (15) is placed within the water jacket space (7) and is threaded into the water jacket at its two ends (16 and 17). Of course this method of placing the vertical shaft in a brass bearing or sleeve would be unnecessary if the cylinders were cast separately. Superimposed on the cylinders are the cylinder heads cast en bloc for each pair of cylinders in the engine in question, though this method of construction is not imperative. A pair of cylinders are shown in cross section through the diameter of the cylinders. (18) illustrates the sparking plug cages, (18) shows the fixed insulated electrode, carrying the sparking anvil (19) on its lower end.

The movable electrode (20) is shown at Fig. 4, having at its lower end the make and break hammer (21), engaged with the anvil (19) prior to separation and formation of the spark. In Fig. 3 they are shown in open circuit. (22) is a closely coiled spiral spring tending to bring the hammer (21) in contact with the anvil (19); (23) is a stronger and more heavy spring counteracting the pull of the lighter spring (22) thus opening the circuit between the hammer and the anvil and thereby producing the spark. Surrounding this lighter spring (22) is a barrel (24) carrying on its upper end a trigger (25). This trigger. (25) is engaged and actuated by the pins or intermediate triggers (26) contained in the openings (27) which are placed in different but parallel planes in the outside circular faceof the timing ring (28). These intermediate triggers (26) are further actuated by the spark lugs (29) on the upper face of the rotary cam plate 10), these spark lugs being either integral or affixed to the cam plate. These various parts showing the sparking mechanism are more clearly shown in Figs. 3 and 4. In Figs. 2 and 4 are also clearly shown the actuating rod or link (30), by which the retardation or advancing of the spark is made constant and uniform for all cylinders. This link is adjustable by the turnbuckle or screw (31), the link itself being connected to each timing ring by proper means at points (32), thesepoints of'attachment (32) being so located that movement of the timing rings is made angularly constant and parallel for all such rings.

Figs. '5 and 6 show different horizontal cross sections of a pair of cylinders as has been stated above, Fig. 5 showing the inlet chamber (35) and the exhaust chamber (36) Fig. 6 shows the water jackets (37). These Figs. 5 and 6 also show my valves which are placed in cages fastened into the heads by screw threads, bolts 01' by any other adaptable means. In the drawings in question I show them screwed in (39) in the usual way but in practice they will be screwed in on the breech-block or interrupted thread system. .The valve stems have springs (40) sufficient to bring the valves back to their seats, when released from downward pressure by the onward rotation of the lugs (12). Figs. 5and 6 also show the peculiar system of my valve placement, which, as has been stated generally above,

are on one or more concentric circular lines 7 l/Vhile two concentric lines of travel are here shown for the location of the valves, in a four or siX cylmder machme, the crank throws and the reduction ratio between the crank shaft and the cam shaft might require a placement on 7 three or fourof such concentric circles and a larger number of valve lugs than is here shown in the drawings. It may now be stated that the common center of all these concentric circular lines of travel on which are placed my valves and spark plugs is the center of rotation of the cam shaft. Figs. 3and 4 also show clearly the sparking lugs (29) which, being afliXed to and rotating as part of the cam plate (10) press out the intermediate triggers (26) through the openings (27.) in the circular face of the timing ring (28), imparting movement to the triggers (25) thereby pressing the ha1nmer (21) on the lower end of the movable electrode 20) into contact with the anvil (19) at the lower end of the fixed electrode (18). The rotation of the cam plate (10) and its attached sparking lugs (29) releases the outward pressure on the intermediate trigger (26) and the heavy spring (23) breaks the contact of the hammer (21) and the anvil (19) thereby producin the spark. This backward movement of the trigger (25) under the impulse of the spring (23) also presses the intermediate trigger (26) face of the timing ring (28) to await another return of its proper sparking cam (29).

shaped piece of metal, with means to fasten back into its respective opening (2'?) in the 7 it centrally on the cam shaft (9) with which it revolves. The under side of the cam plateFig. 7 shows the cam plate upside downis divided into eight equal sectors of forty-five degrees each, in the engine in question. But it is again evident that this dimension of arc is not imperative except as related to the amount of reduction between the cam and the crank shaft and consequent reduced speed of the cam plate. In the engine under examination, the amount of reduction is four to one, and the sectors are forty-five degrees; a revolution of the cam plate through this amount of sector equaling one hundred and eighty degrees of crank motion. On the under side of the cam plate are placed the lugs (12) which press upon the valve stems (13) and actuate the valves (14) these lugs (12) are placed on circles having a common center at the center of rotation of the cam shaft (9) they are placed perpendicular to the plane of the cam plate and have a face or line of bearing commensurate with the portion of the cam plate which equals one hundred and eighty degrees of crank movement; in other words the angular length or bearing of the valve lugs (12) depend on the amount of reduction between thecrank shaft and the cam shaft. In the engine illustrated the reduction ratio is four to one, consequently the bearing length of the lugs is forty-five degrees. These valve lugs are placed ninety degrees apart angularly on their respective lines of travel. This placement of the valve lugs on concentric circular lines of travel is positively related to and governed by the similar placement of the valves as is shown in Figs. 3, 5 and 6. Attention is directed to the shape of these valve lugs (12), which are of trapezoidal outline, the opening or hearing down face making an angle with the plane of the cam plate, consistent and compatible with early valve opening and a minimum resistance to the rotation of the valve cam. This angle between the bearing down face of the lug and the'plane of the cam plate may be uniform throughout or it may be a gradually increasing one, so that greater leverage can be brought to bear at the outset. The closing face of the lug may be perpendicular to the plane of the cam plate, or it may make a small angle with the perpendicular, so that the valves may be eased down on their seats while the intermediate or connecting face is parallel to the cam plate plane. The results of operating the valves by such a cam are a quick opening, a valve that remains open for its full lift for practlcally the whole length of the stroke and an instantaneous cut-0E, with the advantages of lower fuel consumption, complete scavenge of all burnt gases without any back pressure from a gradually closing valve and consequently a purer and larger working charge. Placed on the upper face of this cam plate (10), either fastened to it, integral or made adjustable thereon, are the spark actuating lugs (29) shown in Figs. 3 and 4. There are two pairs of these lugs, the pairs placed in different but parallel planes. Each lug is placed one hundred and eighty degrees apart from its corresponding lug in the same plane. The adjoining lugs of different planes have an angular placement depending on the order of ignition in the different cylinders. Surrounding the lugs (29) as shown in Figs. 1, 2, 3 and 4, is a ring of metal (28), with two openings in its circular face, placed in different but parallel planes, precisely similar to the placement of the spark lugs (29). These -openings are diametrically opposite one another. Freely working within these openings are the intermediate triggers (26) which when engaged by the lugs (29) that correspond to the openings are thrust outward, causing contact of the movable with the fixed electrode, and later resulting in the ignition as has been described above. The line of action of the spark lugs (29) is also circular and is positively related to a like positioning of the spark plugs as shown in Figs. 3, 5 and 6.

In Fig. 3, which shows the correct placement of the valve lugs (12), shown in dot-.

ted lines, and the spark lugs (29), the length of the valve lugs (12), angularly measured, is forty-five degrees, which shows that they act through one stroke of the engine or one hundred and eighty degrees, the cranks of cylinders 1 and 2 being placed one hundred and eighty degrees apart. Rotating the cam through forty-five degrees, corresponding to another stroke of the engine, and we see that cylinder 1 will be at the bottom of its power stroke and lug (12 will begin to bear down upon the exhaust valve (13 of cylinder 1; in cylinder 2 the lug (12) will have ceased to have pressed on the exhaust valve (13) and lug (12) will have reached the intake valve (13) of cylinder 2 Still rotating the cam through another forty-five degrees, we observe in cylinder 1, that as soon as lug; (12) leaves the exhaust valve (139) of cylinder 1, in cylinder 2*, the lug (12) will have passed beyond the intake valve (13 of this cylinder and this cylinder will now be on its compression stroke; another movement of forty-five degrees for the cam plate and we see that lug (12 has passed beyond and closed inlet valve (18) of cylinder 1, that cylinder 2 has completed its compression stroke and the revolution of the cam plate has brought the spark lug (29 up stroke of cylinder 2, at the end of which stroke, sparking lug (29) will be about to cause firing in cylinder 1 This illustrates one half of a complete revolution of the cam plate and has carried the engine through four strokes in-each cylinder. From this is apparent the constant relation that is always maintained between the valve and spark actuation together with the fact that it is a physical impossibility to get the valves and spark out oftime or adjustment. These Figs. 3 and 4 also show my. method of advancing or retarding thespark. As is shown above, the timing rings (28) do not revolve but ride upon the cam plate (10), so that any retardation of the timing rings (28) will carry within them the intermediate triggers (26) and in the same direction that the timing rings may be revolved. A result of any movement is that the sparking lugs (9) will press upon the intermediate triggers (26) at a different time relative to the working of the valves by the valve lugs (12). From this it is seen that if the timing ring (28) is rotated in a direction contrary to the movement of the cam proper (10) and its attached lugs (12), the spark will be advanced and a contrary movement will retard it. The amount of retardation or advancing that the timer is capable of is governed by the length of the bearing face of the intermediate triggers (26) contained in these openings. It is further to be seen that as the timing rings of adjacent cylinders are connected by an adjustable link or actuating rod (30), (shown in Figs. 1, 2 and 3') fitted so that the rotary movement of the timing rings (28) shall be equal and constant at all times, it is physically impossible to change the ignition in one cylinder without causing a like and absolutely equal effect in all the other cylinders. This constant relation for the ignition and valve actuation for a four cylinder engine is shown in Figs. 1 and 2.

Figs. 8 and 9 show the reduction gears by which the motion is transmitted from the crank shaft 5) to the slow speed vertical cam shaft (9). Gears and (41) are integral or attached to one another so that theyrevolve in common; (42) is connected with and rotates with miter (34) (43) rotates on the same shaft as (42) but independently of it; the gear cages (44) and (45) are held in place and in turn hold the gears and pinions in proper relation by means of the shafts on which the gears and pinions rotate. This connection of the cages and shafts is a loose one and the re-. lation established thereby constitutes the only connection between the gears or pinions and cages. The functions of this nest of gears is as follows: Let us suppose that the crank shaft tov be rotating right handed or clockwise, causing a left handed motion of This pinion (42) being (40) rotating with gear 7 (41) imparts motion to gear (43.) with which it is in mesh with a reduction of two to one.

As the vertical cam-shaft (9) is afiixed to gears (43) so that the motion is imparted from the one to the other, the'reduction of motion from the crank shaft (5) to the cam shaft (9), being in the gears illustrated, four to one, fourrevolutions of the crank shaft (5) will result in one revolution of the cam shaft (9). It is further to be seen that motion'can be imparted to thevertical cam shaft (9) by twodistinct methods, 2'. e by holding the horizontal miter (34) stationary and revolving the gear cages (44 and 45'), or by holding the gear cages fixed and stationary and rotating the horizontal miter (34). The difference between these two movements in the gears in question would be as followszlf the cages are held fixed and immovable, and the horizontal miter rotated, the reduction of the motion from the crank shaft to the cam shaft'would be four to one, but if the horizontal gear (34) is held stationary, a-nd the cages rotated, planetary, the reduction of motion will be four 'to three, that is four revolu-u tions of the cages will cause three revolutions of the cam shaft. In the usual operation of the engine, the rotation that will be used 'toprese'rve the proper engine cycles will bethat in which the cagesr'emain fixed, and the horizontal miter (34) is rotated; the movement of the cages will only be used to further adjust the time of valve actuation, while the engine is in motion or at rest. To go further into the valve adjustment, it will be apparent that the nest of gears in question is revoluble in a plane at right angles to the axis of the cam shaft and that any rotation of it causes a similar rotation'of the vertical cam shaft (9) and also of the superimposed cam plate (10). Now referring to Fig. and supposing the engine at rest, it is apparent that any rotation of the cam plate (10) will impart motion in a similar direction to the valve lugs (12) and the spark actuating lugs (29) and change their relative positions to the valve stems (13) and the sparking triggers (26).

Now as I have presumed the engine atrest,

the movement of the cam plate (10) has also changed the relative position of the lugs (12) and (29) to theposition of the piston (which has not moved 'by assumption) and as both valve lugs (12') and spark lugs (29) have moved as a unit, the relative time of valve opening to the spark actuation has not changed. It is therefore seen that as the cam shaft (9) and attached cam plate (10) can be rotated by two different means and not necessarily in the same manner, it follows that these motions can be brought about at the same time, that is when the engine is running, the rotation of the cam shaft (9) by means of the miter gears does not affect the relation of the valve lugs and spark lugs to the piston but that rotation by means of the gear cages has that effect. In order to preserve the constant relation between the valves and the sparking of all the cylinders, the cages are connected by an adjustable link (46) so attached to each gear cage that the distance between the points of attachment of these links to the gear cages shall equal the distance between the centers of cam shafts, with the result that the quadrilateral formed by connecting points of attachment of links and cages and centers of cam shafts will always be a parallelogram, despite rotation of the cages in their own plane.

Fig. 10 illustrates the device or coupling clutch whereby the entire valve motion, timer and sparker are thrown out of gear and come to rest in the event of a backfiring and a consequent reversal of the direction of rotation of the engine. This coupling is shown in Fig. 8 at (33) mounted a above the reduction gears, but in practice the same will be placed between the crank shaft and the reduction gears, or they may be formed together with and become a part of the miter gear (34) depending upon economic engine design, so that the gears will also remain inoperative when any reversal takes place. In the detailed sketch, Fig. 10, the coupling (47) attached to the shaft (9) is operatively connected by means of the pawls (47*). These pawls (47 are forced by spiral springs (47) into the root of the slots (47) while they are in operative association. The root of these slots ex tends on the line (47) to the periphery of the face of the coupling (47 permitting of an inclined wedge motion and forcing the pawls back into the internal recesses of the coupling (33), thereby permitting the pawls (47 to become inoperative. In Fig. 10 the pawls are shown to be four in number and at an angular placement of ninety degrees. This is a modified form of placement for a gear reduction of eight to one, but as the reduction shown in the gears in Fig. 9 has a ratio of four to one, only two points of clutch contact, one hundred and eighty degrees apart, angula-rly, are necessary and the other two could be dispensed with. Both of the clutches above described as to number and placement of points of clutch contact, are applicable to a pair of cylinders only. Where four or more cylinders are employed, there must be only one point of clutch contact for each cam shaft, in order that the order of the cycles in all cylinders may be preserved after a backfiring. If it should be required to employ more than one point of clutch contact, the clutch points that are to operate simultaneously must be so placed that they cannot cooperate with any other. This may be done by placing the different pairs of clutch points in different planes. This application may be reversed, a. 6., the pawls and the springs can be held and retained in (47 and wedged shaped recesses (47) may be formed in the coupling (33) according as economic engine design might render desirable.

While the advantages of my invention are more pronounced where the duplex motion of the cam and its attachments is availed of, still it is conceivable that some design of hydro-carbon engine might require the use of a single reduction, that is a two to one reduction between the crank shaft and the cam shaft. In this case the advantages of my cam with its attached sparking and valve actuating lugs, working as a unit, the placement of the valves and the spark lugs on concentric circular lines with a corresponding placement of the actuating lugs, the positive control of both time of ignition and time of valve actuation, still maintain, with certain minor changes in the angular distribution of the valves, length of bearing face of lugs, etc., as would be determined by the design of the engine in question.

In my drawings and specification I have used a four cylinder, vertical, water cooled, engine working on the four cycle principle, with the valves in the top of the head; as it' is possible to construct the cylinders and the cylinder heads integral. one with the other as well as en bloc, it is my intention to so construct the engine, when the necessity for such an assembly demands it. In the present case. I have only taken the type of engine that I have for illustrative purposes. I therefore do not limit myself to the precise construction and arrangement of parts, as herein described, as the benefits of my unit control system, my valve placement. and slow moving cam plate and control of valve actuation whether engine is in motion or at rest could be favorably applied to the so-called rotary engines, op-' posed or semi-opposed types, also to engines with a valve placement in other locations than in the head proper, and this too, whether they are cooled by water, air or otherwise. It could also be well applied to the two cycle type, which scavenge with a charge of air through driven valves. I again do not wish to limit myself in this respect but desire to avail myself of the various modifications, proportions and structural designs and details as properly fall within the spirit of my invention.

Having thus described my invention, what I claim as new and wish to secure by Letters Patent is as follows:

1. In a hydro-carbon engine comprising a pair of fixed cylinders, pistons therein and a common crank shaft, said cylinders being arranged at spaced intervals along said crank shaft, with the cylinder axes perpendicular to the axis of the crank shaft, inlet and exhaust valves for said cylinders arranged on concentric lines of cam travel, a rotatable cam plate and a plurality of cams on said plate, some of said cams being adapted to operate a valve of one cylinder and the rest of the cams being adapted to operate the remaining valves of both cylinders, when said cam plate is rotated.

2. In a hydro-carbon engine, comprising a pair of fixed cylinders, pistons therein and a common crank shaft, said cylinders being arranged at spaced intervals along said. crank shaft, with the cylinder axes perpendicular to the axis of the crank shaft, inlet and exhaust valves for said cylinders arranged on concentric lines of cam travel, a rotatable cam plate and four cams on said plate, two of said cams being adapted to operate two valves of one cylinder and one valve of the other cylinder and the other two cams being adapted to operate the other valve, when said cam plate is rotated.

3. In an explosive engine, a crank shaft, a pair of pistons and a pair of fixed cylinders, the axes of said cylinders being perpendicular to the crank shaft axis, inlet and exhaust valves for said cylinders, the valves of one cylinder and one valve of the other cylinder being arranged on a circular line of cam travel, a rotatable cam plate and a plurality of cams on said plate, said cams being adapted to operate all the said valves when the plate is rotated.

4. In an explosive engine, a pair of fixed cylinders, longitudinally disposed and a crank shaft, the axes of the said cylinders being perpendicular to the crank shaft axis, inlet and exhaust valves for said cylinders, the valves of one cylinder and one valve of the other cylinder being arranged on one circular line of cam travel and the other valve of the latter cylinder arranged on a second circular line of cam travel concentric with the first, a rotatable cam plate and a plurality of cams on saidcam plate, said cams being adapted to operate all the valves of said pair of cylinders, when the cam plate is rotated. 7

5. In a hydro-carbon engine comprising a pair'of fixed cylinders, pistons therein and a common crank shaft, said cylinders being arranged at spaced intervals along the said crank shaft, with the cylinder axes perpendicular to the crank shaft axis, inlet and exhaust valves for said cylinders, the valves of one cylinder and one valve of the other cylinder being arranged on one circular line of cam travel and the other valve of the latter cylinder arranged on a second circular line of cam travel concentric with the first, a rotatable cam plate and a plurality of cams on said cam plate, some of said cams being adapted to operate the valves arranged on one line of cam travel and some of them adapted to operate the remaining valve, when the cam plate is rotated.

6. In a hydro-carbon engine, a pair of fixed cylinders, pistons therein and a common crank shaft, said cylinders being arranged at spaced intervals along said crank shaft, with the cylinder axes perpendicular to the axis of the crank shaft, inlet and exhaust valves for said cylinders arranged on two concentric lines of cam travel, three valves being located on one line of cam travel and the remaining valve on the other, a rotatable cam plate with a plurality of cams on it, some of said cams being adapted to operate the three valves located on one line of cam travel and some being adapted to operate the other valve, when said cam plate is rotated. V V i .7. In a hydro-carbon engine, a pair of fixed cylinders, pistons therein and acommon crank shaft, said cylinders being armon crank shaft, said cylinders being ar-' ranged at spaced intervals along said crank shaft, with the cylinder axes perpendicular to the axis of the crankshaft, inlet and exhaust valves for said cylinders, the valves of one cylinder and one valve of the other cylinder being arranged on one circular line of cam travel and the other valve of the latter cylinder arranged ,on a second circular line of cam travel concentric with the first, a rotatable cam plate with four cams on it, two of said cams being adapted to operate two valves of one cylinder and one valve of the other cylinder and two eams being adapted to operate the other a common crank shaft, said cylinders being arranged at spaced intervals along said crank shaft, with the cylinder axes perpendicular to the axis of the crank shaft, inlet and exhaust valves for said cylinders arranged on two concentric lines of cam travel, valve operating means consisting of a rotatable cam plate with four cams on it, two of said cams being adapted to operate the two valves of one cylinder and one valve of the other cylinder and two cams being adapted to operate the other valve, when said cam plate is rotated.

In testimony whereof, I have hereunto set my hand, this 28th day of June, 191:2, in the presence of two subscribing witnesses.

GEORGE EDWARD DAVIS.

Witnesses S. R. HIoKERsoN, H. B. SPAUNHORST.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

